When motors and generators having a high quality and a long service life are built, it is a known practice to use an electric insulation system that fulfills the usually wide variety of electric, mechanical and environmental requirements. In this context, in order to vacuum-impregnate and cure the completely wound stator or rotor, a specially modified epoxy resin is used that produces a void-free insulation with sealed surfaces. Particularly in the case of such windings, the stator or rotor spools that have been freed of the old windings first have to be cleaned before they can be fitted with new windings. Up until now, it has been necessary to first remove the epoxy resins that are injected between the stator bar and the laminated core during the impregnation and pressure-compacting process. This work is difficult to carry out, especially with narrow and deep winding grooves, since the resin has to be removed without damaging the laminated core.
Various cleaning devices and methods have already been tried in order to achieve this, but they all entail considerable drawbacks. Thus, for example, according to a known method, a dry-ice cleaning operation is carried out, that is to say, the dry ice causes the epoxy resins adhering to the groove walls to become brittle so that they can be removed manually. All in all, this technique is expensive and uneconomical in very hot or tropical countries.
Another known method proposes cleaning the grooves using a manual belt grinder. This approach entails the risk of damaging the laminated core, in addition to which, with narrow grooves, the problem arises that it is difficult to properly reach everywhere.
Finally, manually scraping or scouring the epoxy resins is also a possibility, but here too, there is a risk of damage to the laminated core, in addition to which the narrow and long grooves are difficult to access. Moreover, these cleaning methods are not conducive to automation and require costly manual processing.